Rapper for electrical precipitation apparatus



April 3, 1951 A. s. GANNONE 2,547,573

RAPPER FOR ELECTRICAL PRECIPITATION APPARATUS File d April 18, 1949 INYENTOR. ANTHONY S, Gmwvo/vs,

47 rozA/E Ys Patented Apr. 3, 1951 RAPPER FOR ELECTRICAL PRECIPITATION APPARATUS Anthony S..Gannne, BoundBrook, N. J., as.-

signor to Research Corporation, New York, N. Y., a corporation of New York Application April 18, 1949, 'Se rial N0..88,081

"7 Claims (Cl. 1837) This invention relates to a rapping device for useonanapparatus for electrical precipitation. of suspended material from gases.

The, principal object of the invention is to provide improved meansfor cleaning and removing precipitated or deposited material adhering to theelectrodes of electrical precipitators.

Aparticularobject of the invention is to pro- Vida-means for cleaning thecollecting electrodes of electrical precipitators by mechanically rapping..or,.jarring single electrodes on groups of.

electrodes independently of the other electrodes, so that only. a minimum amount of deposited material isliberated into the gas stream, thereby eliminatingthe necessity of providing dampers to prevent movement ofthe gas during the rapping period.

Another object is to provide such a device having a number of, rapping or striking members equaltovtheunumber of plate electrodes, and to operate. all of suchelements by a single rapping mechanism, of much smaller size and power than is customarily required to rap or. jar all of the. electrodes simultaneously.

Aiurtherobject of the invention is to provide a device utilizing the efliciency of individually rapping. the collecting electrodes of an electrical precipitator, without the expense of providing individual rapping. mechanism for each electrode which .in large precipitators would be prohibitive.

Thesefand other objects and advantages are provided by. the electrode rapping device of the invention which in its. preferred embodiment comprises a bar extending transversely of the electrodes, striker members .staggered radially along the bar adjacent each electrode to be rapped, means for rotating the bar to bring successivesstriker members into striking position with respect to the corresponding adjacent electrode, and means for reciprocating the bar.

The invention will be more particularly described with reference to the illustrative embodimentsof theinventionshownin the accompanying drawings; in which Fig. 1 is a fragmentary View of an electrical precipitator showing the electrode rapping device of the invention; and

Fig. 2 is an enlarged fragmentary view showing the hammers and anvils of the rapping device.

Electrical precipitators of the Cottrell type generally comprise a casing with inlet and outlet for the gases to be treated, and two groups of opposed electrodes within the casing which are insulated from each other. In operation, the op posed electrodes are maintained at a high potentiaLdifierenceand the. gases to be treated are passed through this strong electric field subjectingthe gases to electronic bombardment and ionization. Free electrons and ions moving under the force of the electric field travel from the discharge electrodes to the collecting or plate elece trodes. In order to maintain the efiiciency of the precipitator the collecting electrodes must be periodically cleaned of the attached particles which increase resistance and cause excessive corona discharge and sparking.

The electrode-cleaning device of the invention,

as shown in Fig. 1 of the drawing is attached-- to the side walls .H of anelectrical precipitator provided with discharge electrodes l2 and .collecting electrodes l3.

In the preferred form of. the invention'a rapping bar 114., journaled in bearings l5 and 15 for :reciprocating and rotary motion, passes" through the. side walls I l of the precipitator perpendicular and adjacent to the lower edge of the" collecting electrodes l3.

Stufiing glands or boxes 16 and I6 secured tothe "precipitator casing provide a gas-proof seal between the precipitator and therapping bar; Additional rapping bar supporting bearings may be incorporated within'the stuffing boxes on installations--requiring additional bearing surfacesfor the reciprocating rapping bar M.

Located at one end of the rapping bar, externally of the precipitator casing l l is the rapping mechanism I! which may consistof any device adaptableto' impart longitudinal. displacement impulses to. the rapping bar. In the form of the invention illustrated the rapping mechanism I1. is .a .double acting compressed air vibrator, for

example, of the type shown in United States Patent 1.8483344 to .C.- E. Salmonson. Stops l8 and I9 attached to the rapping bar 14 may be provided on either side of the rapping mechanismhousing 2-!) to'lim'itthe displacement of the rapping bar.

The principal striking members or hammers 2 l.-

et 28 keyed to the rapping bar M, a free floating ratchet 29, and a ratchet spring 3!! attached at one end to ratchet 29 and at the other end to a spring anchor plate 3| which inturn is'fastened to the end-wall of the ratchet assembly housing Thus it will be seen that as bar I4 is rotated 32. clockwise, fixed ratchet 2B is similarly rotated driving the free floating ratchet 29 out of engagement and compressing the spiral spring 30 until the ratchet 28 has rotated to a position which allows ratchet 29 to drop back into engagement,

imparting a blow against anvil or anvils that are aligned with corresponding hammer pins 2!. V

In order to minimize wear upon hammer pins 2| and anvil plates 22 an electrical relay 33 of any well known type is incorporated in the rapping device to limit and synchronize the actuation of air vibrator 20 and drive motor 23 sothat the air vibrator 20 is only in operation when the hammer pin or pins are in striking position with respect to the corresponding adjacent electrodes and the drive motor is stationary.

A typical cycle of operation comprises striking, for example, two of the electrode plates for ten seconds by reciprocating the rapping bar by the action of the air vibrator. Then the bar is rotated clockwise and as soon as ratchet 29 starts to move away from the fixed part of the ratchet element the air vibrator is stopped and remains stationary until the ratchet is dropped into en gagement again, imparting a blow to a new set.-

of electrode plates to beaugmented by the air vibrator for ten seconds. Then the vibrator is stopped andthe rotation repeated. This cycle may be continuous or timed to operate a fixed period each hour or day depending upon the individual requirement of the recipitator.

From the foregoing description'it willbe seen.

that the present invention provides an improved means for cleaning and removing precipitated or deposited material adhering to, precipitator elec:

trodes whereby the aims, objects and advantages of the invention are fully accomplished.

It will be evident that various modifications may be made in the construction of the device g use of insulated hammers, or rapping bars the device of the invention may be readily adapted for cleaning the discharge electrodes or both collectingand discharge electrodes.

I claim:

1. In an electrical precipitator, having electrodes in spaced relation to each other, an electrode rapping device comprising a rotatable bar extending transversely of the electrodes, striker members positioned in spiral spaced relation along the bar adjacent each electrode to be rapped, means for rotating said bar to bring successive striker members into striking position with respect to the corresponding adjacent electrode and means for reciprocating said bar.

2. In an electrical precipitator an electrode rapping device as defined in claim 1, wherein said bar extends through the walls of the precipitator.

3. .In an electricial precipitator, an electrode rapping device as defined in claim 2, wherein the means'for rotating and reciprocating said bar are positioned outside of the precipitator.

4. In an electrical precipitator having electrodes in spaced relation to each other, an electrode rapping device comprising a rotatable bar extending transversely'of the spaced electrodes, striker members positioned on said bar adjacent each electrode to be rapped, certain of said striker. members projecting in different radial directions alongthe axis of rotation of said bar from other of said striker members, means for rotating said bar to bring certain of said striker members into striking position with respect to the corresponding adjacent electrodes and thereafter to bring other of said striker members into striking position, and means for reciprocating said bar.

5. In an electrical precipitator having electrodes in spaced relation to each other, an elec trode rapping device as defined in claim 4, wherein said rotatable bar extends through the walls ANTHONY S. GANNONE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,286,458 Warren Dec. 13, 1918 1,882,949 

